[D] Fix identity comparison for structs with complex float fields.

[D] Fix identity comparison for structs with complex float fields.

gcc/d/ChangeLog:

2019-01-20  Iain Buclaw  <ibuclaw@gdcproject.org>

	* d-codegen.cc (identity_compare_p): Return false if seen built-in
	type with padding.
	(build_float_identity): Moved here from expr.cc.
	(lower_struct_comparison): Handle real and complex types.
	* d-tree.h (build_float_identity): New.
	* expr.cc (build_float_identity): Move to d-codegen.cc.

gcc/testsuite/ChangeLog:

2019-01-20  Iain Buclaw  <ibuclaw@gdcproject.org>

	* gdc.dg/runnable.d: Add more tests for comparing complex types.

From-SVN: r268104